Simplify OSAllocator.

Source/wtf/PageAllocationAligned.cpp

-/*
- * Copyright (C) 2010 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
- * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
- * THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "config.h"
-#include "PageAllocationAligned.h"
-
-namespace WTF {
-
-PageAllocationAligned PageAllocationAligned::allocate(size_t size, size_t alignment, OSAllocator::Usage usage, bool writable)
-{
-    ASSERT(isPageAligned(size));
-    ASSERT(isPageAligned(alignment));
-    ASSERT(isPowerOfTwo(alignment));
-    ASSERT(size >= alignment);
-    size_t alignmentMask = alignment - 1;
-
-#if OS(DARWIN)
-    int flags = VM_FLAGS_ANYWHERE;
-    if (usage != OSAllocator::UnknownUsage)
-        flags |= usage;
-    int protection = PROT_READ;
-    if (writable)
-        protection |= PROT_WRITE;
-
-    vm_address_t address = 0;
-    vm_map(current_task(), &address, size, alignmentMask, flags, MEMORY_OBJECT_NULL, 0, FALSE, protection, PROT_READ | PROT_WRITE, VM_INHERIT_DEFAULT);
-    return PageAllocationAligned(reinterpret_cast<void*>(address), size);
-#else
-    size_t alignmentDelta = alignment - pageSize();
-
-    // Resererve with suffcient additional VM to correctly align.
-    size_t reservationSize = size + alignmentDelta;
-    void* reservationBase = OSAllocator::reserveUncommitted(reservationSize, usage, writable, false);
-
-    // Select an aligned region within the reservation and commit.
-    void* alignedBase = reinterpret_cast<uintptr_t>(reservationBase) & alignmentMask
-        ? reinterpret_cast<void*>((reinterpret_cast<uintptr_t>(reservationBase) & ~alignmentMask) + alignment)
-        : reservationBase;
-    OSAllocator::commit(alignedBase, size, writable, false);
-
-    return PageAllocationAligned(alignedBase, size, reservationBase, reservationSize);
-#endif
-}
-
-void PageAllocationAligned::deallocate()
-{
-    // Clear base & size before calling release; if this is *inside* allocation
-    // then we won't be able to clear then after deallocating the memory.
-    PageAllocationAligned tmp;
-    std::swap(tmp, *this);
-
-    ASSERT(tmp);
-    ASSERT(!*this);
-
-#if OS(DARWIN)
-    vm_deallocate(current_task(), reinterpret_cast<vm_address_t>(tmp.base()), tmp.size());
-#else
-    ASSERT(tmp.m_reservation.contains(tmp.base(), tmp.size()));
-    OSAllocator::decommitAndRelease(tmp.m_reservation.base(), tmp.m_reservation.size(), tmp.base(), tmp.size());
-#endif
-}
-
-} // namespace WTF